The inclusion of blastomeres into the inner cell mass in early-stage human embryos depends on the sequence of cell cleavages during the fourth division

The fate of the ICM in humans is still unknown, due to the ethical difficulties surrounding experimentation in this field. In this study we have explored the existing time-lapse recording data of embryos in the early stages of development, taking advantage of the large refractile bodies (RBs) within blastomeres as cellular markers. Our study found that the cellular composition of the ICM in humans is largely determined at the time of the fourth division and blastomeres which cleave first to fourth, during the fourth division from 8 cells to 16 cells, have the potential to be incorporated in the ICM

Tea in the Historical Context of East Asia: Cultural Interactions across Borders

(Translated: Jenine Heaton) Session statement 4: Tea viewed from the comparative culture and cultural interactio

Tea and Tea Culture in the Cultural Context and Comparison of East Asia

　東アジアの核地域（中国，朝鮮，日本，琉球，ベトナム）では，非常に長期に亘って茶飲が行われ，それぞれの文化伝統に根ざした茶飲文化が発展してきた。本稿は，文化のハードとソフトの相関性（ 1 ．現代社会における茶飲の軽便化， 2 ．9-10世紀の茶器（中国・越州窯製品など）の輸出期にともなう茶飲文化の伝播， 3 ．17-18世紀の煎茶文化の世界的普及），茶産業が起こした文化変化，言葉と茶あるいは茶器の関係，茶導入時の在地文化の反応，茶と宗教あるいは儀礼，女性とお茶などをテーマに，東アジア各地域を中心に一部は東南アジアやヨーロッパも含めて行った文化比較論である

Acute Effects of Sex Steroid Hormones on Susceptibility to Cardiac Arrhythmias: A Simulation Study

Acute effects of sex steroid hormones likely contribute to the observation that post-pubescent males have shorter QT intervals than females. However, the specific role for hormones in modulating cardiac electrophysiological parameters and arrhythmia vulnerability is unclear. Here we use a computational modeling approach to incorporate experimentally measured effects of physiological concentrations of testosterone, estrogen and progesterone on cardiac ion channel targets. We then study the hormone effects on ventricular cell and tissue dynamics comprised of Faber-Rudy computational models. The “female” model predicts changes in action potential duration (APD) at different stages of the menstrual cycle that are consistent with clinically observed QT interval fluctuations. The “male” model predicts shortening of APD and QT interval at physiological testosterone concentrations. The model suggests increased susceptibility to drug-induced arrhythmia when estradiol levels are high, while testosterone and progesterone are apparently protective. Simulations predict the effects of sex steroid hormones on clinically observed QT intervals and reveal mechanisms of estrogen-mediated susceptibility to prolongation of QT interval. The simulations also indicate that acute effects of estrogen are not alone sufficient to cause arrhythmia triggers and explain the increased risk of females to Torsades de Pointes. Our results suggest that acute effects of sex steroid hormones on cardiac ion channels are sufficient to account for some aspects of gender specific susceptibility to long-QT linked arrhythmias

Clinical outcome of intrauterine infusion of platelet‐rich plasma in patients with recurrent implantation failure

Abstract Purpose This study aimed to evaluate the effectiveness of intrauterine infusion of platelet‐rich plasma (PRP) before embryo transfer (ET) in recurrent implantation failure (RIF) cases. Methods The authors retrospectively analyzed 54 ET cycles involving frozen and thawed high‐quality blastocysts after intrauterine PRP infusion between September 2019 and November 2020. All patients had a history of at least two times of implantation failure on ET. A total of 54 patients were categorized into two groups: thin endometrium (39 patients) and unexplained implantation failure (15 patients). In the thin‐endometrium group, the endometrial thickness (EMT) was <8.0 mm at cycle days 12–14 in the prior ET cycle. Results Among the 54 ET cycles after PRP infusion, 31 (57.4%) were positive for human chorionic gonadotropin (hCG) and 27 (50%) achieved clinical pregnancy, which was significantly better than that in prior ET cycles without PRP infusion (27.2% and 9.6%, respectively). The EMT was not increased at ET date on the PRP cycle compared with that in the prior ET cycle in both patient groups. Moreover, EMT was not different between the hCG‐positive and hCG‐negative groups. Conclusion Although intrauterine PRP infusion had no superior effect on increasing the EMT than conventional therapeutic agents, it resulted in high pregnancy rates in patients experiencing RIF with or without thin endometrium

StemPanTox: a fast and wide-target drug assessment system for tailor-made safety evaluations using personalized iPS cells

iPS細胞で人体への毒性物質をオールマイティに検出するStemPanTox. 京都大学プレスリリース. 2022-06-07.An alternative model that reliably predicts human-specific toxicity is necessary because the translatability of effects on animal models for human disease is limited to context. Previously, we developed a method that accurately predicts developmental toxicity based on the gene networks of undifferentiated human embryonic stem (ES) cells. Here, we advanced this method to predict adult toxicities of 24 chemicals in six categories (neurotoxins, cardiotoxins, hepatotoxins, two types of nephrotoxins, and non-genotoxic carcinogens) and achieved high predictability (AUC = 0.90–1.00) in all categories. Moreover, we screened for an induced pluripotent stem (iPS) cell line to predict the toxicities based on the gene networks of iPS cells using transfer learning of the gene networks of ES cells, and predicted toxicities in four categories (neurotoxins, hepatotoxins, glomerular nephrotoxins, and non-genotoxic carcinogens) with high performance (AUC = 0.82–0.99). This method holds promise for tailor-made safety evaluations using personalized iPS cells